%%
%% The LaTeX Companion, 3ed
%%
%% Example A-3-8 on page II-664 in "Paragraph boxes".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{135.0pt}
%StartShownPreambleCommands
\newcommand\HR{\rule{.5em}{0.4pt}}
%StopShownPreambleCommands

\begin{document}
\HR\begin{minipage}[b]{12mm}
        A A A A A A A A A A A A A A A
\end{minipage}\HR
\begin{minipage}[c]{12mm}
        B B B B B B B B B B B B B B B B B B B B B B B B
\end{minipage}\HR
\begin{minipage}[t]{12mm}
        C C C C C C C
\end{minipage}\HR
\end{document}
